Downhole Cement Plug for Annular Space Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Plugging and abandoning wells with annular spaces between casings is challenging due to the inability of cement to fill these spaces, risking blowouts and requiring expensive large rigs to remove production casing.
Innovation Solution
A downhole plug and abandonment system using a cement plug with a tool string that includes a downhole tubing cutter and stroking tool section, allowing for access and filling of annular spaces with cement without removing the production casing, utilizing a wireline-powered system to create a circumferential opening and ensure a sealed cement plug across the cross-sectional area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement is used to plug the well, then the well is sealed against leakage, but the cement cannot fill the annular space between casing and formation
Solution Approach 1:
The invention divides the plugging system into multiple components: a first tubular structure (production casing), a second tubular structure (inner casing), a packer, and a cement plug. The packer segments the annular space, allowing cement to be contained and pressurized effectively. The cement plug is positioned within the second tubular structure but extends through a circumferential opening to seal the annular space between the first and second tubular structures, achieving reliable sealing despite the segmented architecture.
2Ease of manufacture
If a large rig is used to pull production casing out, then the annular space can be accessed for cementing, but the operation becomes expensive and complex
Solution Approach 1:
The invention employs a nested configuration where the second tubular structure is positioned inside the first tubular structure (production casing). The packer is set within the annular space between these nested tubular structures. The cement plug is inserted through the second tubular structure and extends through a circumferential opening to seal the annular space. This nested arrangement allows access to and cementing of the annular space without requiring removal of the production casing or use of a large rig.
3Reliability
If the cement plug has full cross-sectional coverage, then no flow lines can penetrate, but the plug must extend through the circumferential opening of the second tubular structure
Solution Approach 1:
The circumferential opening in the second tubular structure is pre-formed at a predetermined position before cement plug installation. This preliminary preparation allows the cement plug to be inserted through the second tubular structure and extend through the opening to achieve full cross-sectional coverage and block all flow lines. The pre-positioned opening facilitates easier plug installation compared to forming the opening after plug insertion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient and cost-effective plugging of wells by allowing cement to fill annular spaces without the need for large rigs, ensuring a sealed well without leakage, and reducing operational complexity.
Implementation Method 1
a cutter tool, and wherein the cement plug has an outer diameter being equal to an inner diameter of the first well tubular metal structure
Implementation Method 2
a cement layer between a wall of the borehole and the first well tubular metal structure preventing leakage of the well through the cement layer
Implementation Method 3
a packer arranged between the first well tubular metal structure and the second well tubular metal structure defining an annular space above the packer
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a downhole plug and abandonment system (100) for a well (105), comprising a first well tubular metal structure (101a) having a wall, a second well tubular metal structure (101b) having a wall, the second well tubular metal structure being arranged inside the first well tubular metal structure, the well tubular metal structures having longitudinal extensions and being arranged in a borehole (104) of a well, a packer (350) arranged between the first well tubular metal structure and the second well tubular metal structure defining an annular space (351) above the packer, a first plug (106) arranged in the second well tubular metal structure dividing the second well tubular metal structure into a first part (107) and a second part (108), the first part being closest to a top of the well, and a cement plug (270) arranged in the first part on top of the packer and the plug. Furthermore, the present invention relates to a downhole plug and abandonment method.